Listen to Justin Bieber hop on Billie Eilish's hit song 'Bad Guy'

Teen pop star Billie Eilish has long been open about her love for Canadian singer Justin Bieber. She talked to Ellen DeGeneres about her fandom (in return, DeGeneres pranked Eilish with a fake Bieber jump scare), she gushed about him following her on Instagram and the two finally met for the first time at this year's Coachella.

Now, they've taken their friendship to the next level: collaboration. Eilish has dropped a new version of her hit single, "Bad Guy," featuring a new verse from Bieber. "OMGFFFGGG," she wrote on Instagram today, along with an old photo of herself posing in her bedroom where the walls are covered with Bieber posters. "ANYTHING IS POSSIBLE MAN."

Listen to the new "Bad Guy" below.

Related: Billie Eilish shares her perspective on success, social media and fame

Eilish has become one of the biggest success stories this year in music. Her debut album, When We All Fall Asleep, Where do we Go?, debuted at number 1 on the Billboard 200 and has also topped the charts in Canada, the U.K. and Australia. And even though Bieber announced a hiatus from music earlier this year, he has seemingly gone back on his word and has released a number of new songs since then, including "I Don't Care" with Ed Sheeran and "Don't Check on Me" with Chris Brown and Ink.